R and C++ Integration

Comments (0)

Transcript of R and C++ Integration

by Suz Tolwinski-WardSouped-up R code with C++ Problem: Despite being awesome in so many ways (open-source, extensible, user community, interactivity), sometimes R is too slow (it's interpreted, not compiled).Solution: Rewrite bottlenecks in C++ callable from R with the Rcpp package.real modeling problem: tropical cyclone landfallsDetermine algorithmically whether the simulated TC tracks (red, green) intersect the coastline (blue) from their piecewise linear representations.Solution: check whether each pair of segments from the coastline and the TC track intersect. (Beware the NESTED LOOPS!!!!)Want to be able to do this zillions of times for Monte Carlo sampling of zillions of tracks. Moral of the demo: my C++ implementation, called from R via , is several hundreds of times faster than my plain-old R implementation!Rcpporient3pts <- function(pt1,pt2,pt3){

}include the Rcpp header...use the Rcpp namespace......and export these functions for use within R sessions. (Note: if you create a new C++ file from the Rstudio drop-down menu, it opens a template file for you with the "magical incantations" already filled in.)#include <Rcpp.h>using namespace Rcpp;